Heat dissipation device

ABSTRACT

A heat dissipation device for dissipating heat from an electronic component, includes a heat sink, a centrifugal fan disposed on the heat sink, and a cover board covering the heat sink and located above the centrifugal fan. The cover board defines a plurality of through holes acting as air-intakes of the centrifugal fan.

BACKGROUND

1. Technical Field

The disclosure relates to heat dissipation, and particularly to a heat dissipation device with low noise.

2. Description of Related Art

Electronic components, such as memory banks comprise numerous circuits operating at high speeds and generating substantial amount of heat. Under most circumstances, it is necessary to cool the memory banks to maintain safe operating conditions and assure that the memory banks function properly and reliably. In the past, various approaches have been used to cool electronic components. Typically, a fan is provided to the casing where the memory banks are disposed, which generates airflow towards the memory banks. However, in use, the fan may make a lot of noise.

What is needed, therefore, is a heat dissipation device with low noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, assembled view of a heat dissipation device in accordance with an embodiment of the disclosure.

FIG. 2 is an exploded view of FIG. 1.

DETAILED DESCRIPTION

Referring to FIGS. 1-2, a heat dissipation device in accordance with an exemplary embodiment of the disclosure is disclosed. The heat dissipation device dissipates heat from an electronic component (not shown) mounted on a printed circuit board (not shown). The heat dissipation device comprises a heat sink 10, a centrifugal fan 20 disposed on the heat sink 10, and a cover board 30 covering the heat sink 10 and located above the centrifugal fan 20.

The heat sink 10 is integrally made of a material with high heat conductivity, such as copper, aluminum or an alloy thereof. The heat sink 10 comprises a base 12 and a plurality of fins 14 extending upwardly from a top face of the base 12. The base 12 is a flat, circular plate. A bottom face of the base 12 is attached to the electronic component. A circular receiving portion 16 is defined by the top face of the base 12 and inner circumferential peripheries of the fins 14. The fins 14 are arranged radially relative to the receiving portion 16. The fins 14 are generally perpendicular to the base 12. The fins 14 are spaced from each other. A passage (not labeled) is defined between every two neighboring fins 14 for an airflow flowing through.

The centrifugal fan 20 comprises a rotation axis 22, a magnetic member 24 mounted on the rotation axis 22, a mounting ring 26, and an impeller 28 rotatably engaging with the rotation axis 22. The centrifugal fan 20 is received in the receiving portion 16 of the heat sink 10. A height of the centrifugal fan 20 is slightly less than that of each fin 14 of the heat sink 10. The rotation axis 22 is perpendicular to the base 12 of the heat sink 10.

The cover board 30 is integrally made of a material with high heat conductivity, such as copper, aluminum or an alloy thereof. The cover board 30 is circular, flat, and thin. A circular hole 32 is defined at a center of the cover board 30. A plurality of through holes 34 are defined in the cover board 30. The through holes 34 are correspondingly located above the impeller 28 of the centrifugal fan 20. The through holes 34 are spaced from each other, and arranged evenly relative to the center of the cover board 30. In this embodiment, the through holes 34 are arranged radially relative to the center of the cover board 30. The cover board 30 is attached to top faces of the fins 14 of the heat sink 10. In use, the through holes 34 act as air-intakes of the centrifugal fan 20, and airflow generated by the centrifugal fan 20 directly flow through the passages of the fins 14 of the heat sink 10. The through holes 34 arranged around the circular hole 32 can effectively reduce noise generated by the impeller 28, whereby the heat dissipation device has a quiet working status.

It is to be understood, however, that even though numerous characteristics and advantages of certain embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A heat dissipation device comprising: a heat sink; a centrifugal fan disposed on the heat sink; and a cover board covering the heat sink and located above the centrifugal fan; wherein the cover board defines a plurality of through holes acting as air-intakes of the centrifugal fan.
 2. The heat dissipation device of claim 1, wherein the heat sink comprises a base and a plurality of fins extending upwardly from a top face of the base.
 3. The heat dissipation device of claim 2, wherein a receiving portion is defined by the top face of the base and inner circumferential peripheries of the fins.
 4. The heat dissipation device of claim 3, wherein the fan is received in the receiving portion.
 5. The heat dissipation device of claim 4, wherein a height of the centrifugal fan is less than that of each fin of the heat sink.
 6. The heat dissipation device of claim 3, wherein the fins are arranged radially relative to the receiving portion.
 7. The heat dissipation device of claim 2, wherein the fins are spaced from each other, and a passage is defined between every two neighboring fins.
 8. The heat dissipation device of claim 7, wherein airflow generated by the centrifugal fan directly flow through the passages of the fins.
 9. The heat dissipation device of claim 1, wherein the centrifugal fan comprises a rotation axis, a magnetic member mounted on the rotation axis, a mounting ring, and an impeller rotatably engaging with the rotation axis.
 10. The heat dissipation device of claim 9, wherein the rotation axis is perpendicular to the base of the heat sink.
 11. The heat dissipation device of claim 1, wherein the through holes are located above the centrifugal fan.
 12. The heat dissipation device of claim 1, wherein the through holes are spaced from each other.
 13. The heat dissipation device of claim 1, wherein the through holes are arranged radially relative to a center of the cover board.
 14. The heat dissipation device of claim 1, wherein a circular hole is defined at a center of the cover board.
 15. The heat dissipation device of claim 1, wherein the cover board is attached to a top side of the heat sink. 